Single-beat estimation of right ventricular end-systolic pressure-volume relationship.

Abstract

Assessment of right ventricular (RV) contractility from end-systolic pressure-volume relationships (ESPVR) is difficult due to problems in measuring RV instantaneous volume and to effects of changes in RV preload or afterload. We therefore investigated in anesthetized dogs whether RV ESPVR and contractility can be determined without measuring RV volume and without changing RV preload or afterload. The maximal RV pressure of isovolumic beats (P(max)) was predicted from isovolumic portions of RV pressure during ejecting beats and compared with P(max) measured during the first beat after pulmonary artery clamping. In RV pressure-volume loops obtained from RV pressure and integrated pulmonary arterial flow, end-systolic elastance (E(es)) was assessed as the slope of P(max)-derived ESPVR, pulmonary artery effective elastance (E(a)) as the slope of end-diastolic to end-systolic relation, and coupling efficiency as the E(es)-to-E(a) ratio (E(es)/E(a)). Predicted P(max) correlated with observed P(max) (r = 0.98 +/- 0.02). Dobutamine increased E(es) from 1.07 to 2.00 mmHg/ml and E(es)/E(a) from 1.64 to 2.49, and propranolol decreased E(es)/E(a) from 1.64 to 0.91 (all P < 0.05). After adrenergic blockade, preload reduction did not affect E(es), whereas hypoxia and arterial constriction markedly increased E(a) and somewhat increased E(es) due to the Anrep effect. Low preload did not affect E(es)/E(a) and high afterload decreased E(es)/E(a). In conclusion, in the right ventricle 1) P(max) can be calculated from normal beats, 2) P(max) can be used to determine ESPVR without change in load, and 3) P(max)-derived ESPVR can be used to assess ventricular contractility and ventricular-arterial coupling efficiency.

• Authors: Serge Brimioulle, Pierre Wauthy, Patricia Ewalenko, Benoît Rondelet, Françoise Vermeulen, François Kerbaul, Robert Naeije
• Journal: American journal of physiology. Heart and circulatory physiology (Am J Physiol Heart Circ Physiol) Vol. 284 Issue 5 Pg. H1625-30 (May 2003) ISSN: 0363-6135 [Print] United States
• PMID: 12531727 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cardiotonic Agents
• Vasodilator Agents
• Dobutamine
• Propranolol

Topics

• Animals
• Cardiotonic Agents (pharmacology)
• Dobutamine (pharmacology)
• Dogs
• Hypertension, Pulmonary (physiopathology)
• Myocardial Contraction (drug effects, physiology)
• Predictive Value of Tests
• Propranolol (pharmacology)
• Stroke Volume (drug effects, physiology)
• Vasodilator Agents (pharmacology)
• Ventricular Function, Right (physiology)
• Ventricular Pressure (drug effects, physiology)